Re: [PATCH v3 20/24] pmdomain: core: Default to use of_genpd_sync_state() for genpd providers

[Jon Hunter <jonathanh@nvidia.com>]

Hi Ulf,

On 01/07/2025 12:47, Ulf Hansson wrote:
> Unless the typical platform driver that act as genpd provider, has its own
> ->sync_state() callback implemented let's default to use
> of_genpd_sync_state().
> 
> More precisely, while adding a genpd OF provider let's assign the
> ->sync_state() callback, in case the fwnode has a device and its driver
> doesn't have the ->sync_state() set already. In this way the typical
> platform driver doesn't need to assign ->sync_state(), unless it has some
> additional things to manage beyond genpds.
> 
> Suggested-by: Saravana Kannan <saravanak@google.com>
> Tested-by: Hiago De Franco <hiago.franco@toradex.com> # Colibri iMX8X
> Tested-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com> # TI AM62A,Xilinx ZynqMP ZCU106
> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
> ---
>   drivers/pmdomain/core.c | 9 +++++++++
>   1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/pmdomain/core.c b/drivers/pmdomain/core.c
> index ca47f91b9e91..5cef6de60c72 100644
> --- a/drivers/pmdomain/core.c
> +++ b/drivers/pmdomain/core.c
> @@ -2600,6 +2600,11 @@ static bool genpd_present(const struct generic_pm_domain *genpd)
>   	return ret;
>   }
>   
> +static void genpd_sync_state(struct device *dev)
> +{
> +	return of_genpd_sync_state(dev->of_node);
> +}
> +
>   /**
>    * of_genpd_add_provider_simple() - Register a simple PM domain provider
>    * @np: Device node pointer associated with the PM domain provider.
> @@ -2628,6 +2633,8 @@ int of_genpd_add_provider_simple(struct device_node *np,
>   	if (!dev && !genpd_is_no_sync_state(genpd)) {
>   		genpd->sync_state = GENPD_SYNC_STATE_SIMPLE;
>   		device_set_node(&genpd->dev, fwnode);
> +	} else {
> +		dev_set_drv_sync_state(dev, genpd_sync_state);
>   	}
>   
>   	put_device(dev);
> @@ -2700,6 +2707,8 @@ int of_genpd_add_provider_onecell(struct device_node *np,
>   	dev = get_dev_from_fwnode(fwnode);
>   	if (!dev)
>   		sync_state = true;
> +	else
> +		dev_set_drv_sync_state(dev, genpd_sync_state);
>   
>   	put_device(dev);
>   

Following this change I am seeing the following warning on our Tegra194
devices ...

  WARNING KERN tegra-bpmp bpmp: sync_state() pending due to 17000000.gpu
  WARNING KERN tegra-bpmp bpmp: sync_state() pending due to 3960000.cec
  WARNING KERN tegra-bpmp bpmp: sync_state() pending due to 15380000.nvjpg
  WARNING KERN tegra-bpmp bpmp: sync_state() pending due to 154c0000.nvenc
  WARNING KERN tegra-bpmp bpmp: sync_state() pending due to 15a80000.nvenc

Per your change [0], the 'GENPD_FLAG_NO_SYNC_STATE' is set for Tegra
and so should Tegra be using of_genpd_sync_state() by default?

Thanks
Jon

[0] https://lore.kernel.org/all/20250701114733.636510-10-ulf.hansson@linaro.org/
-- 
nvpublic